Conventionally, a SIM card is an external and removable element in relation to the communication terminal with which it is associated. This is because its aim is to identify a “subscriber” who may decide to change terminal without wishing to change his identifier associated with the SIM card. The latter is therefore arranged in a housing provided in the communication device.
The SIM card can be physically changed during the life of the communication device, for example in order to obtain more functionalities or to change operator.
FIG. 1 shows an example of a conventional SIM card. The chip 10 of the SIM card 1 is arranged on a plastic substrate 11.
During the production of SIM cards, in a phase known as SIM card personalization, the manufacturer places in the SIM card a number of functions requested by the operator and also stores parameters of the operator (for example secret keys, encryption algorithms, etc.).
In the context of M2M applications, the communication modules are often:                hidden within more complex items of equipment (mention may be made for example of the case of the modules hidden within a motor vehicle or a machine);        hidden and difficult to access (mention may be made of the case of water meters in remote geographical areas);        exposed to hostile environments, in particular in terms of temperature, humidity or vibrations.        
Thus, regardless of whether in the field of “handset” communications or in the field of M2M communications, SIM cards are a weak link in the communication device particularly due to the fact that the environmental constraints generally cannot be withstood by the standard packagings of SIM cards. In any case, the quality of the installation and connections is below that of all the other components of the terminal.
Furthermore, SIM cards require that the housing intended to receive them is accessible. This necessary accessibility may substantially complicate the manufacture of the communication device and therefore may make it more expensive.
In addition, the use of this housing causes a certain bulk and increases the amount of time taken to develop the applications installed on the device, in particular due to the fact that some of the signals from the module must be routed towards the SIM card.